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Diffstat (limited to 'node_modules/postcss-minify-selectors/src/index.js')
| -rw-r--r-- | node_modules/postcss-minify-selectors/src/index.js | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/node_modules/postcss-minify-selectors/src/index.js b/node_modules/postcss-minify-selectors/src/index.js new file mode 100644 index 00000000..9276ff2b --- /dev/null +++ b/node_modules/postcss-minify-selectors/src/index.js @@ -0,0 +1,260 @@ +'use strict'; +const parser = require('postcss-selector-parser'); +const canUnquote = require('./lib/canUnquote.js'); + +const pseudoElements = new Set([ + '::before', + '::after', + '::first-letter', + '::first-line', +]); + +/** + * @param {parser.Attribute} selector + * @return {void} + */ +function attribute(selector) { + if (selector.value) { + if (selector.raws.value) { + // Join selectors that are split over new lines + selector.raws.value = selector.raws.value.replace(/\\\n/g, '').trim(); + } + if (canUnquote(selector.value)) { + selector.quoteMark = null; + } + + if (selector.operator) { + selector.operator = /** @type {parser.AttributeOperator} */ ( + selector.operator.trim() + ); + } + } + + selector.rawSpaceBefore = ''; + selector.rawSpaceAfter = ''; + selector.spaces.attribute = { before: '', after: '' }; + selector.spaces.operator = { before: '', after: '' }; + selector.spaces.value = { + before: '', + after: selector.insensitive ? ' ' : '', + }; + + if (selector.raws.spaces) { + selector.raws.spaces.attribute = { + before: '', + after: '', + }; + + selector.raws.spaces.operator = { + before: '', + after: '', + }; + + selector.raws.spaces.value = { + before: '', + after: selector.insensitive ? ' ' : '', + }; + + if (selector.insensitive) { + selector.raws.spaces.insensitive = { + before: '', + after: '', + }; + } + } + + selector.attribute = selector.attribute.trim(); +} + +/** + * @param {parser.Combinator} selector + * @return {void} + */ +function combinator(selector) { + const value = selector.value.trim(); + selector.spaces.before = ''; + selector.spaces.after = ''; + selector.rawSpaceBefore = ''; + selector.rawSpaceAfter = ''; + selector.value = value.length ? value : ' '; +} + +const pseudoReplacements = new Map([ + [':nth-child', ':first-child'], + [':nth-of-type', ':first-of-type'], + [':nth-last-child', ':last-child'], + [':nth-last-of-type', ':last-of-type'], +]); + +/** + * @param {parser.Pseudo} selector + * @return {void} + */ +function pseudo(selector) { + const value = selector.value.toLowerCase(); + + if (selector.nodes.length === 1 && pseudoReplacements.has(value)) { + const first = selector.at(0); + const one = first.at(0); + + if (first.length === 1) { + if (one.value === '1') { + selector.replaceWith( + parser.pseudo({ + value: /** @type {string} */ (pseudoReplacements.get(value)), + }) + ); + } + + if (one.value && one.value.toLowerCase() === 'even') { + one.value = '2n'; + } + } + + if (first.length === 3) { + const two = first.at(1); + const three = first.at(2); + + if ( + one.value && + one.value.toLowerCase() === '2n' && + two.value === '+' && + three.value === '1' + ) { + one.value = 'odd'; + + two.remove(); + three.remove(); + } + } + + return; + } + + selector.walk((child) => { + if (child.type === 'selector' && child.parent) { + const uniques = new Set(); + child.parent.each((sibling) => { + const siblingStr = String(sibling); + + if (!uniques.has(siblingStr)) { + uniques.add(siblingStr); + } else { + sibling.remove(); + } + }); + } + }); + + if (pseudoElements.has(value)) { + selector.value = selector.value.slice(1); + } +} + +const tagReplacements = new Map([ + ['from', '0%'], + ['100%', 'to'], +]); + +/** + * @param {parser.Tag} selector + * @return {void} + */ +function tag(selector) { + const value = selector.value.toLowerCase(); + + if (tagReplacements.has(value)) { + selector.value = /** @type {string} */ (tagReplacements.get(value)); + } +} + +/** + * @param {parser.Universal} selector + * @return {void} + */ +function universal(selector) { + const next = selector.next(); + + if (next && next.type !== 'combinator') { + selector.remove(); + } +} + +const reducers = new Map( + /** @type {[string, ((selector: parser.Node) => void)][]}*/ ([ + ['attribute', attribute], + ['combinator', combinator], + ['pseudo', pseudo], + ['tag', tag], + ['universal', universal], + ]) +); + +/** + * @type {import('postcss').PluginCreator<void>} + * @return {import('postcss').Plugin} + */ +function pluginCreator() { + return { + postcssPlugin: 'postcss-minify-selectors', + + OnceExit(css) { + const cache = new Map(); + const processor = parser((selectors) => { + const uniqueSelectors = new Set(); + + selectors.walk((sel) => { + // Trim whitespace around the value + sel.spaces.before = sel.spaces.after = ''; + const reducer = reducers.get(sel.type); + if (reducer !== undefined) { + reducer(sel); + return; + } + + const toString = String(sel); + + if ( + sel.type === 'selector' && + sel.parent && + sel.parent.type !== 'pseudo' + ) { + if (!uniqueSelectors.has(toString)) { + uniqueSelectors.add(toString); + } else { + sel.remove(); + } + } + }); + selectors.nodes.sort(); + }); + + css.walkRules((rule) => { + const selector = + rule.raws.selector && rule.raws.selector.value === rule.selector + ? rule.raws.selector.raw + : rule.selector; + + // If the selector ends with a ':' it is likely a part of a custom mixin, + // so just pass through. + if (selector[selector.length - 1] === ':') { + return; + } + + if (cache.has(selector)) { + rule.selector = cache.get(selector); + + return; + } + + const optimizedSelector = processor.processSync(selector); + + rule.selector = optimizedSelector; + cache.set(selector, optimizedSelector); + }); + }, + }; +} + +pluginCreator.postcss = true; +module.exports = pluginCreator; |